According to the 2005 Ford F-250 owners manual :
" regular " unleaded , ( 87 octane ) is used in the 5.4 liter V8 and the 6.8 liter
V10 engines
87 octane
87 octane ( unless its the supercharged 5.4 L then 91 octane )
87 octane
87 for a 6.8 v10....just read it straight out of the owners manual
87 octane unleaded
regular unleaded - 87 octane
" regular " unleaded - 87 octane
" regular " unleaded , 87 octane
regular unleaded - 87 octane
Most likely 87 or above
Ford recommends regular unleaded for this vehicle. 87 octane fuel.
87 octane is recommended